textproduct: Albany

SYNOPSIS

A warm front will bring some rain to eastern New York and western New England tonight. Some isolated to scattered showers will persist on Wednesday associated with a low pressure system and a cold front. A much colder air mass will build in for Thanksgiving with blustery and cold conditions with lake effect snow showers continuing through Friday, as some heavier snow totals may occur over the western Adirondacks.

SHORT TERM /THROUGH THURSDAY/

As of 228 PM EST...Clouds will continue to thicken and lower this afternoon with light rainfall beginning to spread across the region from southwest to northeast in the late afternoon into the early evening. The low to mid level warm advection will increase across the region for periods of light rainfall ahead of the warm front and a dampening out short-wave south of the region. The rainfall may be briefly moderate in intensity. A notable low-level jet of 35-45 KT at 850 hPa will focus the moisture ahead of the boundary. It will be breezy with south/southwest 10-20 mph. Temps will be mild and due to wet bulb cooling with lows 40-45F in the valleys and mid and upper 30s over the higher terrain. Some patchy fog may occur in spots. Total rainfall will be generally two tenths to a half an inch across the forecast area.

Tomorrow...the forecast area breaks into a warm sector, as the warm front moves towards the St Lawrence River Valley. It will be breezy with spotty showers ahead of a cold front and a wave of low pressure moving towards southeast Ontario. A few gusty showers or even an isolated rumble of thunder may occur ahead of the cold front across the southwest Adirondacks and the western Mohawk Valley. Some weak instability is ahead of the front. Isolated showers may product wind gusts of 30-45 mph. High will run about 10-15 degrees above normal with mid 50s to lower 60s in the lower elevations and upper 40s to mid 50s over the higher terrain.

The front moves across the region in the early evening with the rain showers transitioning to snow showers over the western Dacks. A quick coating to half inch of wet snow may occur there. Brisk conditions occur with the frontal passage with west winds increasing to 10-20 mph with some gusts 25-35 mph. Strong cold advection will sweep across the region in the wake of the front with lows falling back in the lower to mid 30s with some 20s over the higher terrain.

Thanksgiving...looks cold and blustery with west/southwest winds 12-25 mph with some gust 30-40 mph. A closed/compact H500 low will set-up over southeast Ontario and southwest Quebec with a secondary cold front moving across the region on the holiday. Scattered snow showers and flurries will initially impact the southwest Adirondacks, w-central Mohawk Valley and Lake George and southern VT with a more pronounced long axis lake band forming off Lake Ontario during the pm. Some the heavier snow bands may reach extreme northern Herkimer county by nightfall. Total accums may reach 1-2" north and west of Old Forge before the real lake effect cranks up. Highs will be in the upper 20s/lower 30s to lower 40s and might reach their peak before noon. The Winter Storm Watch begins at 4 pm for Herkimer/Hamilton Counties.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Key Messages:

- Winter Storm Watch Thu night until early Sat morning for Herkimer and Hamilton Counties with a 50% confidence of reaching >7" of snowfall especially Thu night and Friday along and north of Route 28.

- Medium confidence in advisory-level snowfall accumulations (30 to 60% of >4" snow over 72 hours) resulting from upslope and lake effect snowbands for the western Mohawk Valley including southern Herkimer County.

- Medium confidence in advisory-level wind gusts (30-70% >40 mph) across the Mohawk Valley, eastern Catskills, Capital Region, north/central Taconics and the higher terrain of western New England on Friday.

Thanksgiving night through Friday...lake effect snow bands will impact portions of eastern NY. The lake band off Lake Ontario initially has a southwest to west low-level trajectory and then pivots or transitions to a west to northwest trajectory by Friday morning. This transitory lakeband could impact the morning drivers out for the after Thanksgiving holiday sales. We maintained the Winter Storm Watch for Herkimer and Hamilton Counties, though warning level snowfall amounts are not expected at this time in southern Herkimer County yet. The Watch supports 7" or more of snow at a point in the western Adirondacks Thu late through Fri. The quick movement of the band may limit higher totals. However, a multi-lake connection is possible with a well aligned band due to moderate-extreme lake- induced instability. Advisories may be needed for portions of the Mohawk Valley (southern Herkimer Co. and maybe Fulton/Montgomery Counties). Right now, 6-12" is possible into Saturday across northern Herkimer and western Hamilton Counties and 2-6" over the western Mohawk Valley. Light snow amounts of a coating to less than an inch are possible from the Capital Region north and east and also over th eastern Catskills. The southern Greens may get upslope snow tallies of a few inches. It will be blustery and cold. Lows in the 20s to around 30F and highs on Friday will be close to 10 degrees below normal with mid and upper 30s in the lower elevations and 20s over the higher terrain. The 90th percentile of the NBM was used for winds and gusts Thu night thru Friday and gusts 40 mph or greater are possible for the higher terrain of western New England, the eastern Catskills, Taconics, and the Greater Capital Region based on the LREFs.

The winds gradually subside Fri night and the lake effect becomes narrow multi-bands in northwest flow heading into Saturday morning. High pressure builds in with a dry and very cold day for the holiday weekend. Lows Fri night into the teens over the higher terrain and 20s over the rest of the forecast area. High pressure will bring sunny/mostly sunny skies and cold conditions Sat pm due to subsidence with highs in the lower to mid 30s in the valleys and 20s to lower 30s over the higher terrain.

High pressure moves east of the New England Sat night into Sun. Clouds increase ahead of the next system approaching from the west-central Great Lakes Region. Temps modify to seasonable readings on Sunday, so expect some scattered rain/snow showers to move in during the day. The snow showers will be mainly above 1500 ft in the pm. The cold front moves across the region Sun night into Mon with another surge of cold air with temps falling back below normal Mon-Tue. Some lake effect snow showers and flurries may briefly occur with light accums over the western Dacks and western Mohawk Valley. High pressure may briefly build in Mon night into Tue with dry but cold conditions. Temps will finish the week below normal.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

Through 00z Thursday...Rain has overspread all the TAF sites early this evening. The steady rain will result in conditions quickly worsening to MVFR initially, then IFR through the rest of the evening. Even LIFR conditions may occur overnight into early Wednesday morning due to low cigs and patchy fog in an increasingly moist air mass. The widespread rain should taper off to scattered showers around 05z-06z. Gradual improvement to MVFR is expected late Wednesday morning into the afternoon at most sites, except KGFL may remain with IFR cigs through much of the day. Widely scattered -SHRA expected Wednesday, but most of the time looks dry.

Surface winds tonight will be southerly around 3-8 kt, except 8-12 kt with gusts to 20 kt at KALB through the evening. Winds will remain southerly on Wednesday at 3-8 kt. Will mention low level wind shear at all TAF sites from 00z to around or shortly after 06z Wednesday as a southerly jet of 35-45 kt at 2000 ft AGL moves overhead.

Outlook...

Wednesday Night: Moderate Operational Impact. Breezy. Likely SHRA. Thanksgiving Day: Moderate Operational Impact. Windy With Gusts To 34 kts. NO SIG WX. Thursday Night: Moderate Operational Impact. Windy With Gusts To 31 kts. Chance of SHSN. Friday: Moderate Operational Impact. Windy With Gusts To 37 kts. Chance of SHSN. Friday Night: Moderate Operational Impact. Windy With Gusts To 31 kts. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. Slight Chance of SHSN. Sunday: Moderate Operational Impact. Chance of SHRA...SHSN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Winter Storm Watch from Thursday afternoon through Saturday morning for NYZ032-033-038. MA...None. VT...None.